Lead frame and method for manufacturing lead frame

Abstract

To simplify adjusting a position where a plating layer is formed in a lead and improve the accuracy of positioning.SOLUTION: A lead frame has a frame body, a lead, a first plating layer, and a second plating layer. The frame body has a through-hole. The lead is connected to the frame body. The first plating layer is formed on a surface of the lead. The second plating layer is formed around the through-hole and on a surface of the frame body.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lead frame and a method for manufacturing a lead frame. [Background technology]

[0002] In recent years, semiconductor devices have become known in which semiconductor elements such as IC (Integrated Circuit) chips are mounted on a metal lead frame. That is, a semiconductor device may be formed by mounting a semiconductor chip on one surface of a plurality of leads extending from a lead frame and sealing the semiconductor chip with a resin such as epoxy resin.

[0003] When a semiconductor chip is mounted on one surface of a lead, solder is applied to the electrodes of the semiconductor chip, and the electrodes of the semiconductor chip are disposed on one surface of the lead via the solder. Then, for example, the solder is melted and solidified by a reflow process, so that the electrodes of the semiconductor chip and the lead are joined via the solder, and the semiconductor chip is mounted on one surface of the lead. At that time, if the solder is in direct contact with a metal such as copper, which is the material of the lead, the solder does not wet and spread sufficiently on the surface of the lead, and it is considered that the bonding strength between the semiconductor chip and the lead is reduced.

[0004] In response to this, from the viewpoint of improving the bonding property, a technique has been proposed in which a plating layer made of silver or the like that has high wettability with solder is formed on one surface of the lead. The plating layer is formed, for example, by applying a resist for plating to the surface of the lead, removing a part of the resist by exposure and development using a photomask having a predetermined mask pattern, and then performing electrolytic plating using a plating solution for silver plating. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-077747 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a lead frame having a plating layer formed on one surface of the lead, the electrodes of the semiconductor chip are disposed on the plating layer via solder. Therefore, it is important that the plating layer is formed at a predetermined target position on the lead. Therefore, after manufacturing the lead frame, it is confirmed whether the plating layer is formed at the target position on the lead.

[0007] Specifically, after the lead frame is manufactured, the position of the plating layer on one surface of the lead is measured using a measuring device. If the measurement results in a deviation in the formation position of the plating layer, the alignment position of the photomask used to form the plating layer is corrected.

[0008] However, when the position of the plating layer on one side of the lead is measured using a measuring device, it takes time to perform an accurate measurement because the lead and the plating layer on one side of the lead are fine. Furthermore, if this measurement is performed for multiple leads, the total measurement time becomes longer. As a result, it may take a long time to adjust the formation position of the plating layer on the lead.

[0009] The disclosed technology has been made in consideration of the above, and aims to provide a lead frame and a method for manufacturing a lead frame that can simplify adjustment of the formation position of a plating layer relative to a lead and improve positional accuracy. [Means for solving the problem]

[0010] In one embodiment, the lead frame disclosed in the present application has a frame body, a lead, a first plating layer, and a second plating layer. A through hole is formed in the frame body. The lead is connected to the frame body. The first plating layer is formed on one surface of the lead. The second plating layer is formed on the one surface of the frame body around the through hole. Effect of the Invention

[0011] According to one aspect of the lead frame disclosed in the present application, it is possible to simplify adjustment of the formation position of the plating layer relative to the lead, and to improve the positional accuracy. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a specific example of an assembly of lead frames according to the first embodiment. [Diagram 2] FIG. 2 is a plan view showing the structure of the lead frame according to the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a plan view showing a specific example of the structure of the plating layer. [Diagram 5] FIG. 5 is a plan view showing another specific example of the structure of the plating layer. [Figure 6] FIG. 6 is a flowchart showing a method for manufacturing a lead frame according to the first embodiment. [Figure 7] FIG. 7 is a diagram showing a specific example of the structure of the metal plate. [Figure 8] FIG. 8 is a diagram showing a specific example of the etching resist layer forming step. [Figure 9] FIG. 9 is a diagram showing a specific example of the etching process. [Figure 10] FIG. 10 is a diagram showing a specific example of the etching resist layer peeling step. [Figure 11] FIG. 11 is a diagram showing a specific example of a plating resist forming step. [Figure 12A] FIG. 12A is a diagram showing a specific example of an exposure step. [Figure 12B] FIG. 12B is a diagram showing a specific example of the exposure step. [Figure 13] FIG. 13 is a diagram for explaining the alignment of the photomask. [Figure 14] FIG. 14 is a plan view showing the structure of the alignment mark. [Figure 15]FIG. 15 is a diagram showing a specific example of the development process. [Figure 16] FIG. 16 is a diagram showing a specific example of the plating process. [Figure 17] FIG. 17 is a diagram showing a specific example of a plating resist peeling step. [Figure 18] FIG. 18 is a diagram for explaining an example of the formation of a plating layer. [Figure 19] FIG. 19 is an enlarged plan view showing an example of a state of a plating layer on a lead frame after the plating resist has been peeled off. [Figure 20] FIG. 20 is a diagram for explaining another example of the formation of a plating layer. [Figure 21] FIG. 21 is an enlarged plan view showing another example of the state of the plating layer on the lead frame after the plating resist has been peeled off. [Figure 22] FIG. 22 is a flowchart showing the method for manufacturing the semiconductor device according to the first embodiment. [Diagram 23] FIG. 23 is a diagram showing a specific example of a semiconductor element mounting process. [Figure 24] FIG. 24 is a diagram showing a specific example of the molding process. [Diagram 25] FIG. 25 is a diagram showing the structure of a semiconductor device. [Figure 26] FIG. 26 is a plan view showing the structure of the lead frame according to the second embodiment. [Figure 27] FIG. 27 is a cross-sectional view taken along line XXVII-XXVII in FIG. [Figure 28] FIG. 28 is a plan view showing a specific example of the structure of the plating layer. [Figure 29] FIG. 29 is a plan view showing another specific example of the structure of the plating layer. [Diagram 30] FIG. 30 is a diagram showing a specific example of the exposure step. [Diagram 31] FIG. 31 is a diagram showing a specific example of the development process. [Diagram 32] FIG. 32 is a diagram showing a specific example of the plating process. [Diagram 33]FIG. 33 is a diagram showing a specific example of a plating resist peeling step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the lead frame and the manufacturing method of the lead frame disclosed in the present application will be described in detail with reference to the drawings. Note that the disclosed technology is not limited to these embodiments.

[0014] (First embodiment) Fig. 1 is a diagram showing a specific example of a lead frame assembly according to the first embodiment. As shown in Fig. 1, the lead frame 100 is manufactured as an assembly in which a plurality of lead frames 100 are connected via a frame body 110. In the example shown in Fig. 1, three assemblies (75 lead frames 100 in total) each including 25 lead frames 100 connected in 5 rows and 5 columns are manufactured by performing etching, plating, etc. on a metal plate made of, for example, copper or a copper alloy.

[0015] The frame body 110 is composed of an outer frame 111 and an inner frame 112 connected to the outer frame 111. One lead frame 100 is formed in an area surrounded by the outer frame 111 and the inner frame 112, or in an area surrounded by the inner frame 112. The outer frame 111 is formed with a through hole 111a used for measuring the position of the plating layer, and a through hole 111b used for positioning the photomask. As an example, the through hole 111b is circular in a plan view.

[0016] By manufacturing an assembly of a plurality of lead frames 100 in this manner, the lead frames 100 can be manufactured efficiently, leading to cost reduction. The plurality of lead frames 100 manufactured as an assembly are singulated after semiconductor elements are mounted thereon to form individual semiconductor devices. The outer shape of each lead frame 100 is, for example, a square with each side measuring 3 to 7 mm, and a thickness of 0.1 to 0.25 mm.

[0017] Fig. 2 is a plan view showing the structure of the lead frame 100 according to the first embodiment. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 2 shows an enlarged view of one lead frame 100 surrounded by a dashed line shown in Fig. 1. The lead frame 100 has a frame body 110 and a plurality of leads 120.

[0018] The frame body 110 defines the outer periphery of one lead frame 100 and supports the leads 120. The upper surface of the frame body 110 and the upper surface of the leads 120 are located in the same plane. The frame body 110 is composed of an outer frame 111 and an inner frame 112 connected to the outer frame 111. In an assembly of the lead frames 100, there are lead frames 100 surrounded only by the inner frame 112 and lead frames 100 surrounded by the outer frame 111 and the inner frame 112. FIG. 2 shows the lead frame 100 surrounded by the outer frame 111 and the inner frame 112. When a semiconductor device is formed using the lead frame 100, the lead frame 100 is cut at the dashed line L1 in FIG. 2, and the leads 120 are separated from the frame body 110 (i.e., the outer frame 111 and the inner frame 112).

[0019] When an electronic component such as a semiconductor element is mounted on the lead frame 100, the lead 120 forms a terminal that electrically connects the electronic component to an external component. The lead 120 is formed so as to extend from the frame body 110 (the outer frame 111 or the inner frame 112) toward the center of the area surrounded by the frame body 110 (the outer frame 111 or the inner frame 112). On the upper surface side of the lead frame 100 on which the semiconductor element is mounted, a plating layer 125 (an example of a first plating layer) is formed on the lead 120. Specifically, the lead 120 has a first portion 121 connected to the frame body 110 (the outer frame 111 or the inner frame 112) and a second portion 122 that is thinner than the first portion 121, and the plating layer 125 is formed on the top surface of the tip of the second portion 122. When a semiconductor element is mounted on the lead frame 100, the semiconductor element is flip-chip connected to the plating layer 125 by solder. Then, when the semiconductor element mounted on the lead frame 100 is sealed with sealing resin to form a semiconductor device, the lower surface of the lead 120 (first portion 121) and the side surface cut from the frame body 110 are exposed from the sealing resin to form terminals of the semiconductor device.

[0020] In this embodiment, as shown in, for example, FIG. 2 and FIG. 3, a through hole 111a is formed in the outer frame 111, and a plating layer 115 (an example of a second plating layer) is formed around the through hole 111a on the upper surface of the outer frame 111. As described later in the description of the manufacturing method of the lead frame 100, the positional relationship between the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant. Therefore, by forming the plating layer 115 around the through hole 111a, the manufacturer of the lead frame 100 can measure the amount of misalignment of the plating layer 125 on the upper surface of the lead 120 based on the positional relationship between the plating layer 115 and the through hole 111a. This allows the manufacturer to easily measure the amount of misalignment of the plating layer 125 by simply checking the positional relationship between the plating layer 115 and the through hole 111a by visual inspection, for example, without measuring the misalignment of the plating layer 125 using a measuring device. As a result, the time required to measure the amount of misalignment of plating layer 125 is shortened, and the time required to adjust the formation position of plating layer 125 relative to lead 120 can be shortened. The positional relationship between plating layer 115 and through hole 111a may be confirmed by image processing using an imaging device. In this case, too, since plating layer 115 and through hole 111a are larger than plating layer 125, image processing becomes easier and can be completed in a short time.

[0021] Fig. 4 is a plan view showing a specific example of the structure of plating layer 115. Fig. 4 shows the upper surfaces of outer frame 111 and lead 120. Fig. 4 also shows the formation position of plating layer 115 when plating layer 125 is formed at a predetermined target position on the upper surface of lead 120.

[0022] 4, for example, the through hole 111a has a circular shape in a plan view. The plating layer 115 has an inner peripheral edge and an outer peripheral edge which are similar in shape to the outer peripheral edge of the through hole 111a in a plan view, and has an inner diameter D i The plating layer 115 has a circular ring shape with a diameter equal to the diameter of the through hole 111a. In other words, the plating layer 115 is provided so as to surround the through hole 111a.

[0023] As explained later in the manufacturing method of the lead frame 100, the positional relationship between the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant. Therefore, by forming the plating layer 115 into such a ring shape, for example, the amount of misalignment between the inner peripheral edge of the plating layer 115 and the outer peripheral edge of the through hole 111a can be regarded as the amount of misalignment of the plating layer 125 from a target position on the upper surface of the lead 120. This allows the manufacturer of the lead frame 100 to easily measure the amount of misalignment of the plating layer 125 simply by visually measuring the amount of misalignment between the inner peripheral edge of the plating layer 115 and the outer peripheral edge of the through hole 111a.

[0024] That is, as shown in Fig. 4, when plating layer 125 is formed at a target position on the upper surface of lead 120, the inner peripheral edge of plating layer 115 is positioned so as to overlap with the outer peripheral edge of through hole 111a. Therefore, the manufacturer of lead frame 100 can easily confirm the amount of misalignment between the inner peripheral edge of plating layer 115 and the outer peripheral edge of through hole 111a, for example, by visual inspection, and can easily measure the amount of misalignment of plating layer 125. In the example of Fig. 4, the manufacturer can confirm that the amount of misalignment between the inner peripheral edge of plating layer 115 and the outer peripheral edge of through hole 111a is "0", and can measure the amount of misalignment of plating layer 125 as "0".

[0025] In addition, the inner diameter D of the plating layer 115 i The diameter of the through hole 111a is the diameter D of the plating layer 125. l 4). This improves the visibility of the misalignment between the inner periphery of the plating layer 115 and the outer periphery of the through hole 111a, thereby improving the measurement accuracy of the misalignment between the inner periphery of the plating layer 115 and the outer periphery of the through hole 111a. The leads 120 are formed finely in order to connect the electrodes of the semiconductor element. In contrast, the outer frame 111 is required to have a certain degree of strength in order to hold the lead frame 100. Therefore, the width of the outer frame 111 (width in the left-right direction in FIG. 4) is formed wider than the width of the leads 120 (width in the up-down direction in FIG. 4). Therefore, the inner diameter D of the plating layer 115 iThe diameter of the through hole 111a is the diameter D of the plating layer 125. l In addition, the inner diameter D of the plating layer 115 can be formed larger than the inner diameter D of the plating layer 115. i The diameter of the through hole 111a may be formed to be larger than the width of the lead 120 (the width in the vertical direction in FIG. 4).

[0026] Fig. 5 is a plan view showing another specific example of the structure of plating layer 115. Fig. 5 shows the upper surfaces of outer frame 111 and lead 120. Fig. 5 also shows the formation position of plating layer 115 in the case where plating layer 125 is formed shifted from a predetermined target position on the upper surface of lead 120. The target position is the position indicated by the dashed line in Fig. 5.

[0027] As described later in the manufacturing method of the lead frame 100, the positional relationship between the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant. Therefore, as shown in FIG. 5, when the plating layer 125 is formed shifted from the target position on the upper surface of the lead 120, the inner edge of the plating layer 115 is shifted from the outer edge of the through hole 111a by the shift amount Δd between the plating layer 125 and the target position. Therefore, the manufacturer of the lead frame 100 can easily confirm the shift amount of the positional shift between the inner edge of the plating layer 115 and the outer edge of the through hole 111a by visual inspection, for example, and can easily measure the shift amount of the positional shift of the plating layer 125. In the example of FIG. 5, the manufacturer can confirm that the shift amount of the positional shift between the inner edge of the plating layer 115 and the outer edge of the through hole 111a is "Δd", and can measure the shift amount of the positional shift of the plating layer 125 as "Δd".

[0028] Next, a method for manufacturing the lead frame 100 configured as above will be described by way of a specific example with reference to Fig. 6. Fig. 6 is a flow chart showing the method for manufacturing the lead frame 100 according to the first embodiment. The steps described below are performed on a group of lead frames 100 as shown in Fig. 1, for example, but below, a specific example of each step will be described with attention to one lead frame 100 shown in Fig. 2.

[0029] First, as shown in Fig. 7, for example, a metal plate 200 that will be the base material of the lead frame 100 is prepared (step S101). Fig. 7 is a diagram showing a specific example of the structure of the metal plate 200. The material of the metal plate 200 may be a metal such as copper or a copper alloy. The thickness of the metal plate 200 may be, for example, about 0.1 to 0.25 mm.

[0030] When the metal plate 200 is prepared, an etching resist layer having a predetermined opening is formed (step S102). That is, a photosensitive resist is laminated on the upper and lower surfaces of the metal plate 200. For example, a dry film resist (DFR) can be used as the photosensitive resist. Next, the photosensitive resist is exposed and developed, so that an etching resist layer 210 having a predetermined opening is formed on the upper and lower surfaces of the metal plate 200, as shown in FIG. 8. FIG. 8 is a diagram showing a specific example of the etching resist layer forming step. An opening 211 is formed on the upper surface side of the metal plate 200 in a portion where the through-etching process is performed. Also, an opening 212 is formed on the upper surface side of the metal plate 200 in a portion where the through-etching process is performed to form the through-hole 111a. Also, an opening 213 is formed on the lower surface side of the metal plate 200 in a portion where the through-etching process is performed and a portion where the half-etching process is performed. Also, an opening 214 is formed on the lower surface side of the metal plate 200 in a portion where the through-etching process is performed to form the through-hole 111a.

[0031] The metal plate 200 on which the etching resist layer 210 is formed is immersed in an etching solution and etched (step S103). Specifically, by immersing the metal plate 200 in an etching solution such as sulfuric acid-hydrogen peroxide or persulfate, the surface of the metal plate 200 exposed from the openings of the etching resist layer 210 is dissolved and formed into the shape of the lead frame 100.

[0032] That is, for example, as shown in Fig. 9, in the region where the upper and lower surfaces are exposed from the openings 211 and 213, the metal plate 200 is dissolved from the upper and lower surfaces, and the leads 120 are formed in the region surrounded by the outer frame 111 and the inner frame 112. Fig. 9 is a diagram showing a specific example of the etching step. Furthermore, at the same time as the formation of the leads 120, through holes 111a are formed in the outer frame 111.

[0033] In this manner, by etching the metal plate 200, a frame body 110 consisting of the outer frame 111 and the inner frame 112, and leads 120 are formed. Furthermore, a through hole 111a is formed in the outer frame 111. Although not shown in FIG. 9, a through hole 111b (see FIG. 1) is formed in the outer frame 111 at the same time as the through hole 111a.

[0034] When the etching is completed, the etching resist layer 210 is stripped using, for example, an amine-based or non-amine-based stripping liquid (step S104), to obtain a lead frame 100 having a frame body 110 consisting of an outer frame 111 and an inner frame 112, and leads 120. That is, as shown in Fig. 10, for example, a lead frame 100 is obtained in which the leads 120 are formed to extend from the outer frame 111 and the inner frame 112, and through holes 111a are formed in the outer frame 111. Fig. 10 is a diagram showing a specific example of the etching resist layer stripping step.

[0035] After the lead frame 100 is formed, a plating resist for plating is formed on the upper surface of the lead 120 (step S105). Specifically, as shown in FIG. 11, for example, a plating resist 220 is formed on the entire surfaces of the outer frame 111, the inner frame 112, and the lead 120. FIG. 11 is a diagram showing a specific example of a plating resist formation step. The plating resist 220 is a negative photosensitive resist, and exposed portions remain. As an example, the plating resist 220 is formed by applying or electrodepositing a photosensitive liquid resist onto the lead frame 100.

[0036] Then, exposure is performed using a photomask having a mask pattern covering the plating target portion of the lead 120, and the plating resist 220 in the portion not covered by the mask pattern is hardened (step S106). Specifically, as shown in, for example, FIG. 12A and FIG. 12B, a photomask 230 having a mask pattern in the portion where the plating layers 115, 125 are to be formed is placed on the lead frame 100. FIG. 12A and FIG. 12B are diagrams showing a specific example of the exposure step. Note that FIG. 12A shows a side cross section of the lead frame 100 and the photomask 230, and FIG. 12B shows the top surface of the photomask 230. FIG. 12A and FIG. 12B show a part of the photomask 230. The photomask 230 is formed of, for example, a light-transmitting film or glass, and has mask patterns 230a, 230b made of a non-light-transmitting material corresponding to the portions where the plating layers 115, 125 are to be formed. The mask pattern 230a corresponds to the portion where the plating layer 125 is to be formed, and the mask pattern 230b corresponds to the portion where the plating layer 115 is to be formed. Then, the photomask 230 is aligned with respect to the lead frame 100. Then, the plating resist 220 is hardened by exposure using the aligned photomask 230, except for a part of the upper surface of the lead 120 (flip chip connection portion) and a portion around the through hole 111a on the upper surface of the outer frame 111. In addition, in FIG. 12A, the portion of the plating resist 220 that is hardened by exposure is shown as being filled in black. The portion of the plating resist 220 that is hardened by exposure becomes a remaining portion that remains after development. In other words, the formation positions of the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 are determined by exposure and development of the plating resist 220 using one photomask 230. Therefore, the positional relationship between the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant.

[0037] 12B, in photomask 230, the positional relationship between mask pattern 230b corresponding to the portion where plating layer 115 is to be formed and mask pattern 230a corresponding to the portion where plating layer 125 is to be formed is constant. Therefore, on the upper surface of lead frame 100, the positional relationship between plating layer 115 and plating layer 125 is constant.

[0038] Here, the alignment of the photomask 230 with respect to the lead frame 100 will be described with reference to Figs. 13 and 14. The photomask 230 has an alignment mark 231 in addition to a mask pattern corresponding to the portions where the plating layers 115 and 125 are formed. Fig. 13 is a diagram for explaining the alignment of the photomask 230. Fig. 13 shows the portion of the photomask 230 in Figs. 12A and 12B where the alignment mark 231 is formed. Fig. 13 shows how an exposure device that exposes the plating resist 220 aligns the photomask 230.

[0039] 13 includes a camera 241, an actuator 242, and a control unit 243. The camera 241 photographs the alignment mark 231 of the photomask 230 and the through hole 111b (see FIG. 1) of the lead frame 100. The actuator 242 can change the position of the photomask 230 based on the control by the control unit 243.

[0040] The control unit 243 is, for example, a processor, and drives the actuator 242 based on image data from the camera 241 to align the photomask 230 with respect to the lead frame using the alignment mark 231. The control unit 243 aligns the photomask 230 with respect to the lead frame, thereby enabling the mask pattern of the photomask 230 to be aligned with the portions of the leads 120 to be plated.

[0041] 14 is a plan view showing the structure of the alignment mark 231. As shown in FIG. 14, as an example, the alignment mark 231 of the photomask 230 is formed in a ring shape. For example, the alignment mark 231 is formed in a ring shape surrounding the circular through hole 111b in a plan view. The control unit 243 performs positioning (alignment) of the photomask 230 so that the center of the alignment mark 231 coincides with the center of the through hole 111b of the lead frame 100. Then, the control unit 243 exposes the plating resist 220 using the aligned photomask 230.

[0042] Returning to the explanation of Fig. 6, when the plating resist 220 is hardened by exposure, the plating resist 220 is developed (step S107), and only the hardened remaining portion remains on the surface of the lead frame 100. That is, for example, as shown in Fig. 15, the remaining portion of the plating resist 220 covers the surface of the lead frame 100. As a result, an opening 220a exposing a part of the upper surface of the lead 120 (flip chip connection portion) and an opening 220b exposing a portion around the through hole 111a on the upper surface of the outer frame 111 are formed in the plating resist 220. Fig. 15 is a diagram showing a specific example of the developing step.

[0043] The lead frame 100, from which a part of the upper surface of the lead 120 and a part around the through hole 111a on the upper surface of the outer frame 111 are exposed, is immersed in, for example, a plating solution for silver plating to perform plating (step S108). Specifically, the lead frame 100 is immersed in, for example, a plating solution mainly composed of silver cyanide and potassium cyanide to perform electrolytic plating or electroless plating, thereby forming a plating layer 125 on the upper surface of the lead 120. Simultaneously with the plating layer 125, a plating layer 115 is formed around the through hole 111a on the upper surface of the outer frame 111.

[0044] That is, for example, as shown in Fig. 16, silver contained in the plating solution is precipitated on a part of the upper surface of lead 120 exposed from openings 220a and 220b of plating resist 220 and on the area around through-hole 111a, forming plating layer 125 and plating layer 115 having a thickness of, for example, 0.1 to 10 µm. Fig. 16 is a diagram showing a specific example of the plating process.

[0045] After the plating layers 125 and 115 are formed, the plating resist 220 is stripped using, for example, an amine-based or non-amine-based stripping solution (step S109), completing the lead frame 100. That is, as shown in Fig. 17, for example, the plating layer 125 is formed on the upper surface of the lead 120, and the lead frame 100 is completed in which the plating layer 115 is formed around the through hole 111a on the upper surface of the outer frame 111. Fig. 17 is a diagram showing a specific example of the plating resist stripping step.

[0046] When the lead frame 100 is completed, the amount of misalignment of the plating layer 125 on the upper surface of the lead 120 is measured based on the positional relationship between the plating layer 115 and the through hole 111a (step S110). That is, the manufacturer of the lead frame 100 can indirectly measure the amount of misalignment of the plating layer 125 by, for example, visually measuring the amount of misalignment between the inner periphery of the plating layer 115 and the outer periphery of the through hole 111a. Then, based on the measurement result of the misalignment of the plating layer 125 obtained by the manufacturer's visual inspection, the alignment position of the photomask 230 used in the exposure process (step S106) is corrected, and the formation position of the plating layer 125 with respect to the lead 120 is adjusted. The positional relationship between the plating layer 115 and the through hole 111a may be confirmed by image processing using an imaging device. In this case, too, since the plating layer 115 and the through hole 111a are larger than the plating layer 125, image processing becomes easier and processing can be completed in a short time.

[0047] In this way, the manufacturer can indirectly measure the amount of misalignment of plating layer 125 by simply visually checking the positional relationship between plating layer 115 and through hole 111a, for example, without measuring the misalignment of plating layer 125 using a measuring device. As a result, the time required to measure the amount of misalignment of plating layer 125 is shorter than when measuring plating layer 125 using a measuring device, and the time required to adjust the formation position of plating layer 125 relative to lead 120 can be shortened.

[0048] As described above, the lead frame 100 is formed as an assembly of the lead frames 100. At this time, the plating resist 220 formed on the assembly of the lead frames 100 is exposed and developed using a single photomask 230. The plating resist 220 thus exposed and developed is used to form the plating layer 125 on each portion of the assembly of the lead frames 100. Therefore, the positional relationship between the plating layer 125 of the lead frames 100 at any location and the plating layer 115 provided on the outer frame 111 is constant. Therefore, in the assembly of the lead frames 100, the formation position of the plating layer 125 of the lead frames 100 at any location can be confirmed based on the positional relationship between the plating layer 115 formed on the outer frame 111 and the through hole 111a.

[0049] 18 and 19, the formation of plating layer 115 in the case where plating layer 125 is formed at a target position on the upper surface of lead 120 will be described in detail. Fig. 18 is a diagram for explaining an example of the formation of plating layer 115.

[0050] In state 11, a plating resist 220 is formed on the surface of the lead frame 100. State 11 is, for example, the state shown in FIG. 11. Then, as shown in state 12, a photomask 230 having a ring-shaped mask pattern 235 around the through hole 111a, which is the portion where the plating layer 115 is to be formed, is placed on the lead frame 100. This state is the state shown in FIG. 12A. The mask pattern 235 corresponds to the mask pattern 230b in FIGS. 12A and 12B. The mask pattern 235 has a circular ring shape whose inner and outer peripheries are similar in shape to the outer periphery of the through hole 111a in a plan view, and whose inner diameter is the same as the diameter of the through hole 111a.

[0051] In state 12, the alignment of the photomask 230 with respect to the lead frame 100 is successful, and the center of the mask pattern 235 coincides with the center of the through hole 111a. Then, the plating resist 220 is hardened except for the portion around the through hole 111a on the upper surface of the outer frame 111 by exposure using the aligned photomask 230. In state 12, the portion of the plating resist 220 that is hardened by exposure is shown filled in black. The portion of the plating resist 220 that is hardened by exposure becomes the remaining portion that remains after development. At this time, the center of the mask pattern 235 coincides with the center of the through hole 111a, so the portion of the plating resist 220 that is not hardened by exposure becomes a ring shape whose center coincides with the center of the through hole 111a.

[0052] When the plating resist 220 is hardened by exposure to light, the plating resist 220 is developed, and only the hardened remaining portion remains on the surface of the lead frame 100. As a result, as shown in state 13, an opening 220b is formed in the plating resist 220, exposing the portion around the through hole 111a on the upper surface of the outer frame 111. This state is shown in Fig. 15. The portion exposed from the opening 220b of the plating resist 220 around the through hole 111a on the upper surface of the outer frame 111 has a ring shape whose center coincides with the center of the through hole 111a.

[0053] The lead frame 100 in state 13 is immersed in a plating solution and plated. As a result, as shown in state 14, a plating layer 115 is formed around the through hole 111a on the upper surface of the outer frame 111. This state is shown in Fig. 16. The plating layer 115 formed around the through hole 111a has a ring shape whose center coincides with the center of the through hole 111a.

[0054] Then, plating resist 220 is peeled off, completing lead frame 100 in which plating layer 115 is formed around through hole 111a on the upper surface of outer frame 111, as shown in state 15. This state is shown in FIG.

[0055] Fig. 19 is an enlarged plan view showing an example of the state of plating layer 115 on lead frame 100 after peeling off plating resist 220. When plating layer 125 is formed at a target position on the upper surface of lead 120, plating layer 115 is formed so that the center of plating layer 115 coincides with the center of through hole 111a, as shown in Fig. 19. In this case, the formation positions of plating layer 115 and plating layer 125 on lead frame 100 are as shown in Fig. 4.

[0056] 20 and 21, the formation of plating layer 115 in the case where plating layer 125 is formed at a position shifted from a target position on the upper surface of lead 120 will be described in detail. Fig. 20 is a view for explaining another example of the formation of plating layer 115.

[0057] In state 21, a plating resist 220 is formed on the surface of the lead frame 100. State 21 is, for example, the state shown in FIG. 11. Then, as shown in state 22, a photomask 230 having a ring-shaped mask pattern 235 around the through hole 111a, which is the portion where the plating layer 115 is to be formed, is placed on the lead frame 100. This state is the state shown in FIG. 12A. The mask pattern 235 corresponds to the mask pattern 230b in FIGS. 12A and 12B. The mask pattern 235 has a circular ring shape whose inner and outer peripheries are similar in shape to the outer periphery of the through hole 111a in a plan view, and whose inner diameter is the same as the diameter of the through hole 111a.

[0058] In state 22, the alignment of the photomask 230 with respect to the lead frame 100 fails, and the center of the mask pattern 235 does not match the center of the through hole 111a. Then, by exposure using the aligned photomask 230, the plating resist 220 except for the portion around the through hole 111a on the upper surface of the outer frame 111 is hardened. In state 22, the portion of the plating resist 220 that is hardened by exposure is shown filled in black. The portion of the plating resist 220 that is hardened by exposure becomes the remaining portion that remains after development. At this time, since the center of the mask pattern 235 does not match the center of the through hole 111a, the portion of the plating resist 220 that is not hardened by exposure becomes a ring shape whose center does not match the center of the through hole 111a.

[0059] When the plating resist 220 is hardened by exposure to light, the plating resist 220 is developed, and only the hardened remaining portion remains on the surface of the lead frame 100. As a result, as shown in state 23, an opening 220b is formed in the plating resist 220, exposing the portion around the through hole 111a on the upper surface of the outer frame 111. This state is the state shown in Fig. 15. The portion exposed from the opening 220b of the plating resist 220 around the through hole 111a on the upper surface of the outer frame 111 has a ring shape whose center does not coincide with the center of the through hole 111a.

[0060] The lead frame 100 in state 23 is immersed in a plating solution and plated. As a result, as shown in state 24, a plating layer 115 is formed around the through hole 111a on the upper surface of the outer frame 111. This state is shown in Fig. 16. The plating layer 115 formed around the through hole 111a has a ring shape whose center does not coincide with the center of the through hole 111a.

[0061] Then, plating resist 220 is peeled off, completing lead frame 100 in which plating layer 115 is formed around through hole 111a on the upper surface of outer frame 111, as shown in state 25. This state is shown in FIG.

[0062] Fig. 21 is an enlarged plan view showing another example of the state of plating layer 115 on lead frame 100 after peeling off plating resist 220. When plating layer 125 is formed shifted from the target position on the upper surface of lead 120, plating layer 115 is formed in a state in which the center of plating layer 115 is shifted from the center of through hole 111a, as shown in Fig. 21. In this case, the formation positions of plating layer 115 and plating layer 125 on lead frame 100 are as shown in Fig. 5.

[0063] Next, a method for manufacturing a semiconductor device configured using the lead frame 100 will be described by way of a specific example with reference to Fig. 22. Fig. 22 is a flowchart showing the method for manufacturing a semiconductor device according to the first embodiment. Note that, hereinafter, a process for manufacturing a semiconductor device using the lead frame 100 in which a plating layer 125 is formed at a target position on the upper surface of the lead 120 will be described.

[0064] First, a semiconductor element is mounted on the lead 120 of the lead frame 100 (step S121). Specifically, for example, as shown in FIG. 23, the semiconductor element 240 is flip-chip connected to the plating layer 125 on the upper surface of the lead 120. FIG. 23 is a diagram showing a specific example of the semiconductor element mounting process. That is, the electrodes 245 of the semiconductor element 240 are connected to the plating layer 125 by the solder 250. At this time, the connection by the solder 250 is realized by melting and solidifying the solder 250 by a reflow process. In the lead frame 100, since the plating layer 125 is formed at a target position on the upper surface of the lead 120, a sufficient connection surface can be secured for the solder 250 and the plating layer 125, and the bonding property between the semiconductor element 240 and the lead 120 can be improved.

[0065] Then, the semiconductor element 240 mounted on the lead frame 100 is sealed with sealing resin (step S122). Specifically, resin sealing is performed by transfer molding. The lead frame 100 on which the semiconductor element 240 is mounted is accommodated in a metal mold, and fluidized sealing resin is injected into the metal mold. The sealing resin is then heated to a predetermined temperature and hardened, so that, for example, as shown in FIG. 24, sealing resin 260 fills the space around the semiconductor element 240, sealing the semiconductor element 240 mounted on the lead frame 100. FIG. 24 is a diagram showing a specific example of the sealing process.

[0066] When the semiconductor element 240 mounted on the lead frame 100 is sealed with the sealing resin 260, the sealing resin 260 is cut and the leads 120 are cut from the frame 110 at the portion indicated by the dashed line L1 in Fig. 24 (step S123). As a result, the frame 110 is separated and removed from the lead frame 100, and a semiconductor device having the leads 120, the semiconductor element 240 and the sealing resin 260 is completed, for example, as shown in Fig. 25. Fig. 25 is a diagram showing the structure of the semiconductor device. In this semiconductor device, the lower surface of the lead 120 and the side surface cut from the frame 110 are exposed from the lower surface and side surface of the sealing resin 260, and become terminals for connecting to the outside.

[0067] As described above, the lead frame (e.g., lead frame 100) according to the first embodiment has a frame body (e.g., frame body 110), leads (e.g., leads 120), a first plating layer (e.g., plating layer 125), and a second plating layer (e.g., plating layer 115). The frame body has a through hole (e.g., through hole 111a). The leads are connected to the frame body. The first plating layer is formed on one surface (e.g., upper surface) of the lead. The second plating layer is formed on one surface of the frame body around the through hole. As a result, according to the lead frame according to the first embodiment, it is possible to simplify adjustment of the formation position of the plating layer (e.g., plating layer 215) relative to the leads, and to improve positional accuracy.

[0068] Second embodiment The lead frame 100 according to the second embodiment differs from the lead frame 100 according to the first embodiment in the structure of the plating layer 115 which is the second plating layer. Therefore, in the second embodiment, variations in the structure of the plating layer 115 will be mainly described.

[0069] Fig. 26 is a plan view showing the structure of a lead frame 100 according to the second embodiment. Fig. 27 is a cross-sectional view taken along line XXVII-XXVII in Fig. 26. In Fig. 26, the same parts as in Fig. 2 are denoted by the same reference numerals. Fig. 26 shows an enlarged view of one lead frame 100 surrounded by a dashed line shown in Fig. 1.

[0070] In this embodiment, as shown in, for example, FIG. 26 and FIG. 27, a through hole 111a is formed in the outer frame 111 of the frame body 110, and a plating layer 115 (an example of a second plating layer) is formed on the upper surface of the outer frame 111. The plating layer 115 is formed in a solid shape on the upper surface of the outer frame 111. As shown in, for example, FIG. 26, the plating layer 115 has an opening 115a at a position overlapping with the through hole 111a in a plan view. As described later in the manufacturing method of the lead frame 100, the positional relationship between the opening 115a of the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant. Therefore, by providing the opening 115a in the plating layer 115, the manufacturer of the lead frame 100 can measure the amount of misalignment of the plating layer 125 on the upper surface of the lead 120 based on the positional relationship between the opening 115a and the through hole 111a exposed from the opening 115a. This allows the manufacturer to easily measure the amount of misalignment of plating layer 125 by simply visually checking the positional relationship between opening 115a and through hole 111a, for example, without using a measuring device to measure the misalignment of plating layer 125. As a result, the time required to measure the amount of misalignment of plating layer 125 is shorter than in the case of measurement using a measuring device, and the time required to adjust the formation position of plating layer 125 relative to lead 120 can be shortened.

[0071] Fig. 28 is a plan view showing a specific example of the structure of plating layer 115. Fig. 28 shows the upper surfaces of outer frame 111 and lead 120. Fig. 28 also shows the formation position of plating layer 115 when plating layer 125 is formed at a predetermined target position on the upper surface of lead 120.

[0072] 28, the through hole 111a has a circular shape in a plan view. The inner periphery of the opening 115a of the plating layer 115 is similar in shape to the outer periphery of the through hole 111a in a plan view, and has a diameter D o is the diameter D of the through hole 111a t It has a circular shape that is larger than

[0073] As explained later in the manufacturing method of the lead frame 100, the positional relationship between the opening 115a of the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant. Therefore, by forming the opening 115a of the plating layer 115 in such a circular shape, for example, the amount of misalignment between the center of the opening 115a and the center of the through hole 111a can be regarded as the amount of misalignment of the plating layer 125 from a target position on the upper surface of the lead 120. This allows the manufacturer of the lead frame 100 to easily measure the amount of misalignment of the plating layer 125 simply by visually measuring the amount of misalignment between the center of the opening 115a and the center of the through hole 111a.

[0074] That is, as shown in Fig. 28, when plating layer 125 is formed at a target position on the upper surface of lead 120, the center of opening 115a of plating layer 115 is positioned to overlap with the center of through hole 111a. Therefore, the manufacturer of lead frame 100 can easily confirm the amount of misalignment between the center of opening 115a and the center of through hole 111a by, for example, visual inspection, and can easily measure the amount of misalignment of plating layer 125. In the example of Fig. 28, the manufacturer can confirm that the amount of misalignment between the center of opening 115a and the center of through hole 111a is "0", and can measure the amount of misalignment of plating layer 125 as "0".

[0075] In addition, the diameter D of the opening 115a of the plating layer 115 o and the diameter D of the through hole 111a t is the diameter D of the plating layer 125 l This improves the visibility of the misalignment between the center of the opening 115a and the center of the through hole 111a, and therefore improves the measurement accuracy of the misalignment between the center of the opening 115a and the center of the through hole 111a. o and the diameter D of the through hole 111a t may be formed to be larger than the width of the lead 120 (the width in the vertical direction in FIG. 28).

[0076] Fig. 29 is a plan view showing another specific example of the structure of plating layer 115. Fig. 29 shows the upper surfaces of outer frame 111 and lead 120. Fig. 29 also shows the formation position of plating layer 115 in the case where plating layer 125 is formed shifted from a predetermined target position on the upper surface of lead 120. The target position is the position indicated by the dashed line in Fig. 29.

[0077] As explained later in the manufacturing method of the lead frame 100, the positional relationship between the opening 115a of the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant. o When the plating layer 125 is formed at a position shifted from the target position on the upper surface of the lead 120, the center C t The center C of the opening 115a is shifted from the center C of the opening 115a by a shift amount Δd between the plating layer 125 and the target position. o and the center C of the through hole 111a t 29, the manufacturer can easily check the amount of misalignment between the center C of the opening 115a and the plating layer 125, and can easily measure the amount of misalignment between the center C of the opening 115a and the plating layer 125. o and the center C of the through hole 111a t It can be confirmed that the amount of misalignment between the plating layer 125 and the plating layer 126 is "Δd", and the amount of misalignment between the plating layer 125 and the plating layer 126 can be measured as "Δd".

[0078] Next, a method for manufacturing the leadframe 100 according to the second embodiment will be described. The method for manufacturing the leadframe 100 according to the second embodiment is basically the same as the method for manufacturing the leadframe 100 according to the first embodiment shown in Fig. 6. However, the method for manufacturing the leadframe 100 according to the second embodiment differs from the method for manufacturing the leadframe 100 according to the first embodiment in the specific processing contents of steps S106 to S110 in Fig. 6. Therefore, the specific processing contents of steps S106 to S110 in the second embodiment will be described below with reference to Fig. 6.

[0079] After the plating resist 220 is formed in step S105, exposure is performed to harden the plating resist 220 in the portion not covered by the mask pattern of the photomask 230 (step S106). Specifically, as shown in FIG. 30, for example, a photomask 230A having a mask pattern in the portion where the plating layers 115 and 125 are to be formed is placed on the lead frame 100. FIG. 30 is a diagram showing a specific example of the exposure step. The photomask 230A is formed of, for example, a light-transmitting film or glass, and has mask patterns 230Aa and 230Ab made of a non-light-transmitting material corresponding to the portion where the plating layers 115 and 125 are to be formed. The mask pattern 230Aa corresponds to the portion where the plating layer 125 is to be formed, and the mask pattern 230Ab corresponds to the portion where the plating layer 115 is to be formed. Then, the photomask 230A is aligned with the lead frame 100. Then, by exposure using the photomask 230A after alignment, the plating resist 220 is hardened except for a part of the upper surface of the lead 120 (flip chip connection part) and a part surrounding the position overlapping with the through hole 111a in a plan view on the upper surface of the outer frame 111. In addition, in FIG. 30, the part of the plating resist 220 that is hardened by exposure is shown filled in black. The part of the plating resist 220 that is hardened by exposure becomes a remaining part that remains after development. In other words, the formation positions of the opening 115a of the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 are determined by exposure and development of the plating resist 220 using one photomask 230A. Therefore, the positional relationship between the opening 115a of the plating layer 115 and the plating layer 125 on the upper surface of the lead frame 100 is constant.

[0080] When the plating resist 220 is hardened by exposure, the plating resist 220 is developed (step S107), and only the hardened remaining portion remains on the surface of the lead frame 100. That is, for example, as shown in Fig. 31, an opening 220a exposing a part of the upper surface of the lead 120 and an opening 220c exposing a portion surrounding a position overlapping with the through hole 111a in the upper surface of the outer frame 111 in a plan view are formed in the plating resist 220. Fig. 31 is a diagram showing a specific example of the developing step.

[0081] The lead frame 100, from which a part of the upper surface of the lead 120 and a part surrounding a position on the upper surface of the outer frame 111 overlapping with the through hole 111a in a plan view are exposed, is immersed in, for example, a plating solution for silver plating to perform plating (step S108). Specifically, the lead frame 100 is immersed in, for example, a plating solution containing silver cyanide and potassium cyanide as main components to perform electrolytic plating or electroless plating, thereby forming a plating layer 125 on the upper surface of the lead 120. Simultaneously with the plating layer 125, a plating layer 115 is formed around a position on the upper surface of the outer frame 111 overlapping with the through hole 111a in a plan view.

[0082] That is, as shown in Fig. 32, for example, silver contained in the plating solution is precipitated on a portion of the upper surface of lead 120 exposed from openings 220a and 220c of plating resist 220 and on a portion surrounding a position overlapping with through hole 111a of outer frame 111, forming plating layer 125 and plating layer 115 having a thickness of, for example, 0.1 to 10 µm. Fig. 32 is a diagram showing a specific example of the plating process.

[0083] After the plating layer 125 and the plating layer 115 are formed, the plating resist 220 is stripped off using, for example, an amine-based or non-amine-based stripping solution (step S109), and the lead frame 100 is completed. That is, as shown in Fig. 33, for example, the plating layer 125 is formed on the upper surface of the lead 120, and the lead frame 100 is completed in which the plating layer 115 having the opening 115a at a position overlapping with the through hole 111a is formed on the upper surface of the outer frame 111. Fig. 33 is a diagram showing a specific example of the plating resist stripping step.

[0084] When the lead frame 100 is completed, the amount of misalignment of the plating layer 125 on the upper surface of the lead 120 is measured based on the positional relationship between the opening 115a and the through hole 111a exposed from the opening 115a (step S110). That is, the manufacturer of the lead frame 100 can indirectly measure the amount of misalignment of the plating layer 125 by, for example, visually measuring the amount of misalignment between the center of the opening 115a and the center of the through hole 111a. Then, based on the measurement result of the misalignment of the plating layer 125 obtained by the manufacturer's visual inspection, the alignment position of the photomask 230A used in the exposure process (step S106) is corrected, and the formation position of the plating layer 125 with respect to the lead 120 is adjusted. The positional relationship between the opening 115a and the through hole 111a exposed from the opening 115a may be confirmed by image processing using an imaging device. In this case as well, since the openings 115a and the through holes 111a are larger than the plating layer 125, image processing becomes easier and can be completed in a short time.

[0085] In this way, the manufacturer can indirectly measure the amount of misalignment of plating layer 125 by simply visually checking the positional relationship between opening 115a and through hole 111a, for example, without measuring the misalignment of plating layer 125 using a measuring device. As a result, the time required to measure the amount of misalignment of plating layer 125 is shorter than when measuring plating layer 125 using a measuring device, and the time required to adjust the formation position of plating layer 125 relative to lead 120 can be shortened.

[0086] As described above, the lead frame (e.g., lead frame 100) according to the second embodiment has a frame body (e.g., frame body 110), leads (e.g., leads 120), a first plating layer (e.g., plating layer 125), and a second plating layer (e.g., plating layer 115). The frame body has a through hole (e.g., through hole 111a). The lead is connected to the frame body. The first plating layer is formed on one surface (e.g., upper surface) of the lead. The second plating layer is formed on one surface of the frame body and has an opening (e.g., opening 115a) at a position overlapping with the through hole in a plan view. As a result, according to the lead frame according to the second embodiment, it is possible to simplify adjustment of the formation position of the plating layer (e.g., plating layer 215) relative to the lead, and to improve positional accuracy.

[0087] (Modification) In the first embodiment, through hole 111a is circular in plan view, and plating layer 115 has a circular ring shape, but the shape of plating layer 115 can be changed as appropriate according to the planar shape of the outer periphery of through hole 111a. For example, when through hole 111a is polygonal in plan view, plating layer 115 may have a polygonal ring shape whose inner and outer peripheries are similar in shape to the outer periphery of through hole 111a in plan view and whose inner diameter is the same as the diameter of through hole 111a.

[0088] In the second embodiment, the through hole 111a is circular in plan view, and the opening 115a of the plating layer 115 has a circular shape, but the shape of the opening 115a can be changed as appropriate according to the planar shape of the outer periphery of the through hole 111a. For example, when the through hole 111a is polygonal in plan view, the opening 115a of the plating layer 115 may have a polygonal shape whose inner periphery is similar to the outer periphery of the through hole 111a in plan view and whose diameter is larger than the diameter of the through hole 111a.

[0089] Furthermore, in each of the above embodiments, the plating layer 125 has a circular shape in a plan view, but the plating layer 125 may be formed in a polygonal shape, such as a rectangle, in a plan view.

[0090] In addition, in each of the above embodiments, the lead frame 100 is formed by etching the metal plate 200, but the lead frame 100 may be formed by pressing the metal plate 200. In addition, in each of the above embodiments, the lead frame is a QFN (Quad Flat Non-leaded package) type lead frame, but the present invention can be applied to various types of lead frames such as a QFP (Quad Flat Package) type lead frame. [Explanation of symbols]

[0091] 100 Leadframe 110 Frame 111 Outer Frame 111a Through hole 111b Through hole 112 Inner Frame 115a opening 120 Leads 121 Part 1 122 Part 2

Claims

1. A frame body having a through hole formed therein; A lead connected to the frame; A first plating layer formed on one surface of the lead; a second plating layer formed on one surface of the frame and around the through hole; A lead frame comprising:

2. The through hole is circular in plan view, The second plating layer is 2. The lead frame according to claim 1, wherein the lead frame has a ring shape whose inner and outer periphery are similar in shape to the outer periphery of the through hole in a plan view and whose inner diameter is the same as the diameter of the through hole.

3. The inner diameter of the second plating layer and the diameter of the through hole are The lead frame according to claim 2 , wherein the diameter of the first plating layer is larger than the diameter of the first plating layer.

4. The inner peripheral edge of the second plating layer is The lead frame described in claim 2, characterized in that when the first plating layer is formed offset from a target position on one surface of the lead, it is positioned offset from the outer peripheral edge of the through hole by an offset amount between the first plating layer and the target position.

5. A frame body having a through hole formed therein; A lead connected to the frame; A first plating layer formed on one surface of the lead; a second plating layer formed on one surface of the frame and having an opening at a position overlapping the through hole in a plan view; A lead frame comprising:

6. The through hole is circular in plan view, The opening of the second plating layer is 6. The lead frame according to claim 5, wherein the inner periphery has a circular shape similar in shape to the outer periphery of the through hole in a plan view and having a diameter larger than that of the through hole.

7. The diameter of the opening of the second plating layer and the diameter of the through hole are The lead frame according to claim 6 , wherein the diameter of the first plating layer is larger than the diameter of the first plating layer.

8. The center of the opening of the second plating layer is The lead frame described in claim 6, characterized in that when the first plating layer is formed offset from a target position on one surface of the lead, it is positioned offset from the center of the through hole by an amount of offset between the first plating layer and the target position.

9. a step of processing a metal plate to form a frame having a through hole and a lead connected to the frame; forming a first plating layer on one surface of the lead and a second plating layer on one surface of the frame around the through hole by plating a metal; 2. A method for manufacturing a lead frame comprising the steps of:

10. measuring the position of the first plating layer on one surface of the lead based on a positional relationship between the second plating layer and the through hole; The method for manufacturing a lead frame according to claim 9, further comprising:

11. a step of processing a metal plate to form a frame having a through hole and a lead connected to the frame; forming a first plating layer on one surface of the lead by plating a metal, and forming a second plating layer having an opening on one surface of the frame at a position overlapping with the through hole in a plan view; 2. A method for manufacturing a lead frame comprising the steps of:

12. A step of measuring the position of the first plating layer on one surface of the lead based on a positional relationship between the opening and the through hole exposed from the opening. The method for manufacturing a lead frame according to claim 11, further comprising:

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